xref: /freebsd/sys/ufs/ffs/fs.h (revision 952d112864d8008aa87278a30a539d888a8493cd)
1 /*
2  * Copyright (c) 1982, 1986, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	@(#)fs.h	8.13 (Berkeley) 3/21/95
34  * $Id: fs.h,v 1.11 1997/03/23 20:08:22 guido Exp $
35  */
36 
37 #ifndef _UFS_FFS_FS_H_
38 #define _UFS_FFS_FS_H_
39 
40 /*
41  * Each disk drive contains some number of file systems.
42  * A file system consists of a number of cylinder groups.
43  * Each cylinder group has inodes and data.
44  *
45  * A file system is described by its super-block, which in turn
46  * describes the cylinder groups.  The super-block is critical
47  * data and is replicated in each cylinder group to protect against
48  * catastrophic loss.  This is done at `newfs' time and the critical
49  * super-block data does not change, so the copies need not be
50  * referenced further unless disaster strikes.
51  *
52  * For file system fs, the offsets of the various blocks of interest
53  * are given in the super block as:
54  *	[fs->fs_sblkno]		Super-block
55  *	[fs->fs_cblkno]		Cylinder group block
56  *	[fs->fs_iblkno]		Inode blocks
57  *	[fs->fs_dblkno]		Data blocks
58  * The beginning of cylinder group cg in fs, is given by
59  * the ``cgbase(fs, cg)'' macro.
60  *
61  * The first boot and super blocks are given in absolute disk addresses.
62  * The byte-offset forms are preferred, as they don't imply a sector size.
63  */
64 #define BBSIZE		8192
65 #define SBSIZE		8192
66 #define	BBOFF		((off_t)(0))
67 #define	SBOFF		((off_t)(BBOFF + BBSIZE))
68 #define	BBLOCK		((ufs_daddr_t)(0))
69 #define	SBLOCK		((ufs_daddr_t)(BBLOCK + BBSIZE / DEV_BSIZE))
70 
71 /*
72  * Addresses stored in inodes are capable of addressing fragments
73  * of `blocks'. File system blocks of at most size MAXBSIZE can
74  * be optionally broken into 2, 4, or 8 pieces, each of which is
75  * addressable; these pieces may be DEV_BSIZE, or some multiple of
76  * a DEV_BSIZE unit.
77  *
78  * Large files consist of exclusively large data blocks.  To avoid
79  * undue wasted disk space, the last data block of a small file may be
80  * allocated as only as many fragments of a large block as are
81  * necessary.  The file system format retains only a single pointer
82  * to such a fragment, which is a piece of a single large block that
83  * has been divided.  The size of such a fragment is determinable from
84  * information in the inode, using the ``blksize(fs, ip, lbn)'' macro.
85  *
86  * The file system records space availability at the fragment level;
87  * to determine block availability, aligned fragments are examined.
88  */
89 
90 /*
91  * MINBSIZE is the smallest allowable block size.
92  * In order to insure that it is possible to create files of size
93  * 2^32 with only two levels of indirection, MINBSIZE is set to 4096.
94  * MINBSIZE must be big enough to hold a cylinder group block,
95  * thus changes to (struct cg) must keep its size within MINBSIZE.
96  * Note that super blocks are always of size SBSIZE,
97  * and that both SBSIZE and MAXBSIZE must be >= MINBSIZE.
98  */
99 #define MINBSIZE	4096
100 
101 /*
102  * The path name on which the file system is mounted is maintained
103  * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in
104  * the super block for this name.
105  */
106 #define MAXMNTLEN	512
107 
108 /*
109  * The limit on the amount of summary information per file system
110  * is defined by MAXCSBUFS. It is currently parameterized for a
111  * size of 128 bytes (2 million cylinder groups on machines with
112  * 32-bit pointers, and 1 million on 64-bit machines). One pointer
113  * is taken away to point to an array of cluster sizes that is
114  * computed as cylinder groups are inspected.
115  */
116 #define	MAXCSBUFS	((128 / sizeof(void *)) - 1)
117 
118 /*
119  * A summary of contiguous blocks of various sizes is maintained
120  * in each cylinder group. Normally this is set by the initial
121  * value of fs_maxcontig. To conserve space, a maximum summary size
122  * is set by FS_MAXCONTIG.
123  */
124 #define FS_MAXCONTIG	16
125 
126 /*
127  * MINFREE gives the minimum acceptable percentage of file system
128  * blocks which may be free. If the freelist drops below this level
129  * only the superuser may continue to allocate blocks. This may
130  * be set to 0 if no reserve of free blocks is deemed necessary,
131  * however throughput drops by fifty percent if the file system
132  * is run at between 95% and 100% full; thus the minimum default
133  * value of fs_minfree is 5%. However, to get good clustering
134  * performance, 10% is a better choice. hence we use 10% as our
135  * default value. With 10% free space, fragmentation is not a
136  * problem, so we choose to optimize for time.
137  */
138 #define MINFREE		8
139 #define DEFAULTOPT	FS_OPTTIME
140 
141 /*
142  * Per cylinder group information; summarized in blocks allocated
143  * from first cylinder group data blocks.  These blocks have to be
144  * read in from fs_csaddr (size fs_cssize) in addition to the
145  * super block.
146  *
147  * N.B. sizeof(struct csum) must be a power of two in order for
148  * the ``fs_cs'' macro to work (see below).
149  */
150 struct csum {
151 	int32_t	cs_ndir;		/* number of directories */
152 	int32_t	cs_nbfree;		/* number of free blocks */
153 	int32_t	cs_nifree;		/* number of free inodes */
154 	int32_t	cs_nffree;		/* number of free frags */
155 };
156 
157 /*
158  * Super block for an FFS file system.
159  */
160 struct fs {
161 	int32_t	 fs_firstfield;		/* historic file system linked list, */
162 	int32_t	 fs_unused_1;		/*     used for incore super blocks */
163 	ufs_daddr_t fs_sblkno;		/* addr of super-block in filesys */
164 	ufs_daddr_t fs_cblkno;		/* offset of cyl-block in filesys */
165 	ufs_daddr_t fs_iblkno;		/* offset of inode-blocks in filesys */
166 	ufs_daddr_t fs_dblkno;		/* offset of first data after cg */
167 	int32_t	 fs_cgoffset;		/* cylinder group offset in cylinder */
168 	int32_t	 fs_cgmask;		/* used to calc mod fs_ntrak */
169 	time_t 	 fs_time;		/* last time written */
170 	int32_t	 fs_size;		/* number of blocks in fs */
171 	int32_t	 fs_dsize;		/* number of data blocks in fs */
172 	int32_t	 fs_ncg;		/* number of cylinder groups */
173 	int32_t	 fs_bsize;		/* size of basic blocks in fs */
174 	int32_t	 fs_fsize;		/* size of frag blocks in fs */
175 	int32_t	 fs_frag;		/* number of frags in a block in fs */
176 /* these are configuration parameters */
177 	int32_t	 fs_minfree;		/* minimum percentage of free blocks */
178 	int32_t	 fs_rotdelay;		/* num of ms for optimal next block */
179 	int32_t	 fs_rps;		/* disk revolutions per second */
180 /* these fields can be computed from the others */
181 	int32_t	 fs_bmask;		/* ``blkoff'' calc of blk offsets */
182 	int32_t	 fs_fmask;		/* ``fragoff'' calc of frag offsets */
183 	int32_t	 fs_bshift;		/* ``lblkno'' calc of logical blkno */
184 	int32_t	 fs_fshift;		/* ``numfrags'' calc number of frags */
185 /* these are configuration parameters */
186 	int32_t	 fs_maxcontig;		/* max number of contiguous blks */
187 	int32_t	 fs_maxbpg;		/* max number of blks per cyl group */
188 /* these fields can be computed from the others */
189 	int32_t	 fs_fragshift;		/* block to frag shift */
190 	int32_t	 fs_fsbtodb;		/* fsbtodb and dbtofsb shift constant */
191 	int32_t	 fs_sbsize;		/* actual size of super block */
192 	int32_t	 fs_csmask;		/* csum block offset */
193 	int32_t	 fs_csshift;		/* csum block number */
194 	int32_t	 fs_nindir;		/* value of NINDIR */
195 	int32_t	 fs_inopb;		/* value of INOPB */
196 	int32_t	 fs_nspf;		/* value of NSPF */
197 /* yet another configuration parameter */
198 	int32_t	 fs_optim;		/* optimization preference, see below */
199 /* these fields are derived from the hardware */
200 	int32_t	 fs_npsect;		/* # sectors/track including spares */
201 	int32_t	 fs_interleave;		/* hardware sector interleave */
202 	int32_t	 fs_trackskew;		/* sector 0 skew, per track */
203 /* fs_id takes the space of the unused fs_headswitch and fs_trkseek fields */
204 	int32_t	 fs_id[2];		/* unique filesystem id */
205 /* sizes determined by number of cylinder groups and their sizes */
206 	ufs_daddr_t fs_csaddr;		/* blk addr of cyl grp summary area */
207 	int32_t	 fs_cssize;		/* size of cyl grp summary area */
208 	int32_t	 fs_cgsize;		/* cylinder group size */
209 /* these fields are derived from the hardware */
210 	int32_t	 fs_ntrak;		/* tracks per cylinder */
211 	int32_t	 fs_nsect;		/* sectors per track */
212 	int32_t  fs_spc;			/* sectors per cylinder */
213 /* this comes from the disk driver partitioning */
214 	int32_t	 fs_ncyl;		/* cylinders in file system */
215 /* these fields can be computed from the others */
216 	int32_t	 fs_cpg;			/* cylinders per group */
217 	int32_t	 fs_ipg;			/* inodes per group */
218 	int32_t	 fs_fpg;			/* blocks per group * fs_frag */
219 /* this data must be re-computed after crashes */
220 	struct	csum fs_cstotal;	/* cylinder summary information */
221 /* these fields are cleared at mount time */
222 	int8_t   fs_fmod;		/* super block modified flag */
223 	int8_t   fs_clean;		/* file system is clean flag */
224 	int8_t 	 fs_ronly;		/* mounted read-only flag */
225 	int8_t   fs_flags;		/* currently unused flag */
226 	u_char	 fs_fsmnt[MAXMNTLEN];	/* name mounted on */
227 /* these fields retain the current block allocation info */
228 	int32_t	 fs_cgrotor;		/* last cg searched */
229 	struct	csum *fs_csp[MAXCSBUFS];/* list of fs_cs info buffers */
230 	int32_t	 *fs_maxcluster;	/* max cluster in each cyl group */
231 	int32_t	 fs_cpc;		/* cyl per cycle in postbl */
232 	int16_t	 fs_opostbl[16][8];	/* old rotation block list head */
233 	int32_t	 fs_sparecon[50];	/* reserved for future constants */
234 	int32_t	 fs_contigsumsize;	/* size of cluster summary array */
235 	int32_t	 fs_maxsymlinklen;	/* max length of an internal symlink */
236 	int32_t	 fs_inodefmt;		/* format of on-disk inodes */
237 	u_int64_t fs_maxfilesize;	/* maximum representable file size */
238 	int64_t	 fs_qbmask;		/* ~fs_bmask for use with 64-bit size */
239 	int64_t	 fs_qfmask;		/* ~fs_fmask for use with 64-bit size */
240 	int32_t	 fs_state;		/* validate fs_clean field */
241 	int32_t	 fs_postblformat;	/* format of positional layout tables */
242 	int32_t	 fs_nrpos;		/* number of rotational positions */
243 	int32_t	 fs_postbloff;		/* (u_int16) rotation block list head */
244 	int32_t	 fs_rotbloff;		/* (u_int8) blocks for each rotation */
245 	int32_t	 fs_magic;		/* magic number */
246 	u_int8_t fs_space[1];		/* list of blocks for each rotation */
247 /* actually longer */
248 };
249 
250 /*
251  * Filesystem identification
252  */
253 #define	FS_MAGIC	0x011954	/* the fast filesystem magic number */
254 #define	FS_OKAY		0x7c269d38	/* superblock checksum */
255 #define FS_42INODEFMT	-1		/* 4.2BSD inode format */
256 #define FS_44INODEFMT	2		/* 4.4BSD inode format */
257 /*
258  * Preference for optimization.
259  */
260 #define FS_OPTTIME	0	/* minimize allocation time */
261 #define FS_OPTSPACE	1	/* minimize disk fragmentation */
262 
263 /*
264  * Rotational layout table format types
265  */
266 #define FS_42POSTBLFMT		-1	/* 4.2BSD rotational table format */
267 #define FS_DYNAMICPOSTBLFMT	1	/* dynamic rotational table format */
268 /*
269  * Macros for access to superblock array structures
270  */
271 #define fs_postbl(fs, cylno) \
272     (((fs)->fs_postblformat == FS_42POSTBLFMT) \
273     ? ((fs)->fs_opostbl[cylno]) \
274     : ((int16_t *)((u_int8_t *)(fs) + \
275 	(fs)->fs_postbloff) + (cylno) * (fs)->fs_nrpos))
276 #define fs_rotbl(fs) \
277     (((fs)->fs_postblformat == FS_42POSTBLFMT) \
278     ? ((fs)->fs_space) \
279     : ((u_int8_t *)((u_int8_t *)(fs) + (fs)->fs_rotbloff)))
280 
281 /*
282  * The size of a cylinder group is calculated by CGSIZE. The maximum size
283  * is limited by the fact that cylinder groups are at most one block.
284  * Its size is derived from the size of the maps maintained in the
285  * cylinder group and the (struct cg) size.
286  */
287 #define CGSIZE(fs) \
288     /* base cg */	(sizeof(struct cg) + sizeof(int32_t) + \
289     /* blktot size */	(fs)->fs_cpg * sizeof(int32_t) + \
290     /* blks size */	(fs)->fs_cpg * (fs)->fs_nrpos * sizeof(int16_t) + \
291     /* inode map */	howmany((fs)->fs_ipg, NBBY) + \
292     /* block map */	howmany((fs)->fs_cpg * (fs)->fs_spc / NSPF(fs), NBBY) +\
293     /* if present */	((fs)->fs_contigsumsize <= 0 ? 0 : \
294     /* cluster sum */	(fs)->fs_contigsumsize * sizeof(int32_t) + \
295     /* cluster map */	howmany((fs)->fs_cpg * (fs)->fs_spc / NSPB(fs), NBBY)))
296 
297 /*
298  * Convert cylinder group to base address of its global summary info.
299  *
300  * N.B. This macro assumes that sizeof(struct csum) is a power of two.
301  */
302 #define fs_cs(fs, indx) \
303 	fs_csp[(indx) >> (fs)->fs_csshift][(indx) & ~(fs)->fs_csmask]
304 
305 /*
306  * Cylinder group block for a file system.
307  */
308 #define	CG_MAGIC	0x090255
309 struct cg {
310 	int32_t	 cg_firstfield;		/* historic cyl groups linked list */
311 	int32_t	 cg_magic;		/* magic number */
312 	time_t	 cg_time;		/* time last written */
313 	int32_t	 cg_cgx;		/* we are the cgx'th cylinder group */
314 	int16_t	 cg_ncyl;		/* number of cyl's this cg */
315 	int16_t	 cg_niblk;		/* number of inode blocks this cg */
316 	int32_t	 cg_ndblk;		/* number of data blocks this cg */
317 	struct	csum cg_cs;		/* cylinder summary information */
318 	int32_t	 cg_rotor;		/* position of last used block */
319 	int32_t	 cg_frotor;		/* position of last used frag */
320 	int32_t	 cg_irotor;		/* position of last used inode */
321 	int32_t	 cg_frsum[MAXFRAG];	/* counts of available frags */
322 	int32_t	 cg_btotoff;		/* (int32) block totals per cylinder */
323 	int32_t	 cg_boff;		/* (u_int16) free block positions */
324 	int32_t	 cg_iusedoff;		/* (u_int8) used inode map */
325 	int32_t	 cg_freeoff;		/* (u_int8) free block map */
326 	int32_t	 cg_nextfreeoff;	/* (u_int8) next available space */
327 	int32_t	 cg_clustersumoff;	/* (u_int32) counts of avail clusters */
328 	int32_t	 cg_clusteroff;		/* (u_int8) free cluster map */
329 	int32_t	 cg_nclusterblks;	/* number of clusters this cg */
330 	int32_t	 cg_sparecon[13];	/* reserved for future use */
331 	u_int8_t cg_space[1];		/* space for cylinder group maps */
332 /* actually longer */
333 };
334 
335 /*
336  * Macros for access to cylinder group array structures
337  */
338 #define cg_blktot(cgp) \
339     (((cgp)->cg_magic != CG_MAGIC) \
340     ? (((struct ocg *)(cgp))->cg_btot) \
341     : ((int32_t *)((u_int8_t *)(cgp) + (cgp)->cg_btotoff)))
342 #define cg_blks(fs, cgp, cylno) \
343     (((cgp)->cg_magic != CG_MAGIC) \
344     ? (((struct ocg *)(cgp))->cg_b[cylno]) \
345     : ((int16_t *)((u_int8_t *)(cgp) + \
346 	(cgp)->cg_boff) + (cylno) * (fs)->fs_nrpos))
347 #define cg_inosused(cgp) \
348     (((cgp)->cg_magic != CG_MAGIC) \
349     ? (((struct ocg *)(cgp))->cg_iused) \
350     : ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_iusedoff)))
351 #define cg_blksfree(cgp) \
352     (((cgp)->cg_magic != CG_MAGIC) \
353     ? (((struct ocg *)(cgp))->cg_free) \
354     : ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_freeoff)))
355 #define cg_chkmagic(cgp) \
356     ((cgp)->cg_magic == CG_MAGIC || ((struct ocg *)(cgp))->cg_magic == CG_MAGIC)
357 #define cg_clustersfree(cgp) \
358     ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_clusteroff))
359 #define cg_clustersum(cgp) \
360     ((int32_t *)((u_int8_t *)(cgp) + (cgp)->cg_clustersumoff))
361 
362 /*
363  * The following structure is defined
364  * for compatibility with old file systems.
365  */
366 struct ocg {
367 	int32_t	 cg_firstfield;		/* historic linked list of cyl groups */
368 	int32_t	 cg_unused_1;		/*     used for incore cyl groups */
369 	time_t	 cg_time;		/* time last written */
370 	int32_t	 cg_cgx;		/* we are the cgx'th cylinder group */
371 	int16_t	 cg_ncyl;		/* number of cyl's this cg */
372 	int16_t	 cg_niblk;		/* number of inode blocks this cg */
373 	int32_t	 cg_ndblk;		/* number of data blocks this cg */
374 	struct	csum cg_cs;		/* cylinder summary information */
375 	int32_t	 cg_rotor;		/* position of last used block */
376 	int32_t	 cg_frotor;		/* position of last used frag */
377 	int32_t	 cg_irotor;		/* position of last used inode */
378 	int32_t	 cg_frsum[8];		/* counts of available frags */
379 	int32_t	 cg_btot[32];		/* block totals per cylinder */
380 	int16_t	 cg_b[32][8];		/* positions of free blocks */
381 	u_int8_t cg_iused[256];		/* used inode map */
382 	int32_t	 cg_magic;		/* magic number */
383 	u_int8_t cg_free[1];		/* free block map */
384 /* actually longer */
385 };
386 
387 /*
388  * Turn file system block numbers into disk block addresses.
389  * This maps file system blocks to device size blocks.
390  */
391 #define fsbtodb(fs, b)	((b) << (fs)->fs_fsbtodb)
392 #define	dbtofsb(fs, b)	((b) >> (fs)->fs_fsbtodb)
393 
394 /*
395  * Cylinder group macros to locate things in cylinder groups.
396  * They calc file system addresses of cylinder group data structures.
397  */
398 #define	cgbase(fs, c)	((ufs_daddr_t)((fs)->fs_fpg * (c)))
399 #define	cgdmin(fs, c)	(cgstart(fs, c) + (fs)->fs_dblkno)	/* 1st data */
400 #define	cgimin(fs, c)	(cgstart(fs, c) + (fs)->fs_iblkno)	/* inode blk */
401 #define	cgsblock(fs, c)	(cgstart(fs, c) + (fs)->fs_sblkno)	/* super blk */
402 #define	cgtod(fs, c)	(cgstart(fs, c) + (fs)->fs_cblkno)	/* cg block */
403 #define cgstart(fs, c)							\
404 	(cgbase(fs, c) + (fs)->fs_cgoffset * ((c) & ~((fs)->fs_cgmask)))
405 
406 /*
407  * Macros for handling inode numbers:
408  *     inode number to file system block offset.
409  *     inode number to cylinder group number.
410  *     inode number to file system block address.
411  */
412 #define	ino_to_cg(fs, x)	((x) / (fs)->fs_ipg)
413 #define	ino_to_fsba(fs, x)						\
414 	((ufs_daddr_t)(cgimin(fs, ino_to_cg(fs, x)) +			\
415 	    (blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(fs))))))
416 #define	ino_to_fsbo(fs, x)	((x) % INOPB(fs))
417 
418 /*
419  * Give cylinder group number for a file system block.
420  * Give cylinder group block number for a file system block.
421  */
422 #define	dtog(fs, d)	((d) / (fs)->fs_fpg)
423 #define	dtogd(fs, d)	((d) % (fs)->fs_fpg)
424 
425 /*
426  * Extract the bits for a block from a map.
427  * Compute the cylinder and rotational position of a cyl block addr.
428  */
429 #define blkmap(fs, map, loc) \
430     (((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag)))
431 #define cbtocylno(fs, bno) \
432     ((bno) * NSPF(fs) / (fs)->fs_spc)
433 #define cbtorpos(fs, bno) \
434     (((bno) * NSPF(fs) % (fs)->fs_spc / (fs)->fs_nsect * (fs)->fs_trackskew + \
435      (bno) * NSPF(fs) % (fs)->fs_spc % (fs)->fs_nsect * (fs)->fs_interleave) % \
436      (fs)->fs_nsect * (fs)->fs_nrpos / (fs)->fs_npsect)
437 
438 /*
439  * The following macros optimize certain frequently calculated
440  * quantities by using shifts and masks in place of divisions
441  * modulos and multiplications.
442  */
443 #define blkoff(fs, loc)		/* calculates (loc % fs->fs_bsize) */ \
444 	((loc) & (fs)->fs_qbmask)
445 #define fragoff(fs, loc)	/* calculates (loc % fs->fs_fsize) */ \
446 	((loc) & (fs)->fs_qfmask)
447 #define lblktosize(fs, blk)	/* calculates ((off_t)blk * fs->fs_bsize) */ \
448 	((off_t)(blk) << (fs)->fs_bshift)
449 /* Use this only when `blk' is known to be small, e.g., < NDADDR. */
450 #define smalllblktosize(fs, blk)    /* calculates (blk * fs->fs_bsize) */ \
451 	((blk) << (fs)->fs_bshift)
452 #define lblkno(fs, loc)		/* calculates (loc / fs->fs_bsize) */ \
453 	((loc) >> (fs)->fs_bshift)
454 #define numfrags(fs, loc)	/* calculates (loc / fs->fs_fsize) */ \
455 	((loc) >> (fs)->fs_fshift)
456 #define blkroundup(fs, size)	/* calculates roundup(size, fs->fs_bsize) */ \
457 	(((size) + (fs)->fs_qbmask) & (fs)->fs_bmask)
458 #define fragroundup(fs, size)	/* calculates roundup(size, fs->fs_fsize) */ \
459 	(((size) + (fs)->fs_qfmask) & (fs)->fs_fmask)
460 #define fragstoblks(fs, frags)	/* calculates (frags / fs->fs_frag) */ \
461 	((frags) >> (fs)->fs_fragshift)
462 #define blkstofrags(fs, blks)	/* calculates (blks * fs->fs_frag) */ \
463 	((blks) << (fs)->fs_fragshift)
464 #define fragnum(fs, fsb)	/* calculates (fsb % fs->fs_frag) */ \
465 	((fsb) & ((fs)->fs_frag - 1))
466 #define blknum(fs, fsb)		/* calculates rounddown(fsb, fs->fs_frag) */ \
467 	((fsb) &~ ((fs)->fs_frag - 1))
468 
469 /*
470  * Determine the number of available frags given a
471  * percentage to hold in reserve.
472  */
473 #define freespace(fs, percentreserved) \
474 	(blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \
475 	(fs)->fs_cstotal.cs_nffree - ((fs)->fs_dsize * (percentreserved) / 100))
476 
477 /*
478  * Determining the size of a file block in the file system.
479  */
480 #define blksize(fs, ip, lbn) \
481 	(((lbn) >= NDADDR || (ip)->i_size >= smalllblktosize(fs, (lbn) + 1)) \
482 	    ? (fs)->fs_bsize \
483 	    : (fragroundup(fs, blkoff(fs, (ip)->i_size))))
484 #define dblksize(fs, dip, lbn) \
485 	(((lbn) >= NDADDR || (dip)->di_size >= smalllblktosize(fs, (lbn) + 1)) \
486 	    ? (fs)->fs_bsize \
487 	    : (fragroundup(fs, blkoff(fs, (dip)->di_size))))
488 
489 /*
490  * Number of disk sectors per block/fragment; assumes DEV_BSIZE byte
491  * sector size.
492  */
493 #define	NSPB(fs)	((fs)->fs_nspf << (fs)->fs_fragshift)
494 #define	NSPF(fs)	((fs)->fs_nspf)
495 
496 /*
497  * Number of inodes in a secondary storage block/fragment.
498  */
499 #define	INOPB(fs)	((fs)->fs_inopb)
500 #define	INOPF(fs)	((fs)->fs_inopb >> (fs)->fs_fragshift)
501 
502 /*
503  * Number of indirects in a file system block.
504  */
505 #define	NINDIR(fs)	((fs)->fs_nindir)
506 
507 extern int inside[], around[];
508 extern u_char *fragtbl[];
509 
510 #endif
511